Method of and means for cementing well formations



Dec. 30, 1941. v, M 2,268,010-

METHOD OF AND MEANS FOR CEMENTING WELL FORMATIONS Fil ed April 15, 19392 SheetsShet 1 graze/WWO Dec. 30, 1941 v. E. BAUM 2,268,010

METHOD OF AND MEANS FOR CEMENTING WELL FORMATIONS Filed April 15, 1939 2Sheets-Sheet 2 awe/WM Vic for 5. 6620177 ous methods have been vsuificient volume to Patented Dec. 30, 194i METHOD OF AND MEANS FORCEMENTING WELL FORMATION S Victor E. Baum, Tulsa,

Texas Okla, assignor to Merla. Tool Corporation, Dallas, Tex., a.corporation of Application April 15, 1939, Serial No. 267,991 3 Claims.(01. 166-1) This invention relates to new and useful im-.

provements in methods of and means for cementing well formations.

In the drilling of wells for oil and gas, it

the usual practice to drill the well down to the producing sand orformation and'set a casing above such formation, after which drilling iscontinued into the oil or gas sand or formation. It rather frequentlyoccurs that the drill bit penetrates a water sand or formation which maybe immediately below and adjacent to the producing formation, with theresult that the water from the water producing formation admixes withthe oil and interferes with the flow of the oil from the well. In manyinstances, the water may cone or channel upwardly, and practically killthe well so that the flow from the oil and gas producing formation issubstantially cut off. 7

Where the well bore is drilled through the oil and gas producingformation into the water sand or formation therebelow, it has beencommon practice to introduce cement into the bottom of.

the bore to provide a cement plug therein; Vari-=.

employed for introducing this cement but cement plugs have been foundunsatisfactory because the water eventually seeps around them and aftera time flows in kill the well. In order to completely close the waterformation with'cement it is necessary that the cement be forced deeplyinto the formation so as to obviate the possibility of flow around thecement. However, difliculty has been experienced in forcing cement intothe water formation without also forcing said cement upwardly into theoil sands or formation. i It is, therefore, one object of this inventionto provide an improved method of efliciently sealing off the waterproducing sands or formation without affecting the oil and gas.producing formation, whereby danger of destruction of the well by wateris eliminated. An important object of the invention is to provide animproved method of cementing the water 4 producing formation below anoil and gas producing formation, wherein the cement is forced laterallyinto the water stratum to fill up the pores and interstices thereof soas to prevent a flow of water from said stratum into the well bore orinto the oil and gas producing formation.

A particular object of the invention is topro vide an improved methodfor cementing the water stratum which includes,'maintaining a fluidpreser than that maintained in the bore, whereby in elevation, of anformation and introducing cement into the bottom of the bore under apressure slightly greatsaid cement is directed outwardly and radially ofthe bore and is forced into the water stratum to seal off the same.

A particular object of theinvention is to provide an improved methodwherein a column of cement is introduced into the well bore and itsdirection and rate of movement is controlled by controlled pressureapplied to opposite ends of said column.

Another object of the invention is to provide I an improved apparatusfor cementing wells which includes a tubular conductor for conduct ingthe cement to the bottom of the well, together with a valve in the lowerend of the conductor capable of normally sustaining the weight of thecolumn of cemen said valve being operated by a differential in pressurethereacross.

whereby a surface control of the operation'of the valve may bemaintained and the cement may be effectively forced into the formation.

A further object'of the invention is to provide an improved method ofthe character described for cementing oil the water sand from the oilformation which includes the step of packing on? between said sand andsaid formation, whereby such sealing aids in directing the cement in alateral or radial direction from the well bore, whereby the water sandmay be sealed oil without affecting the oil formation A constructiondesigned to%arry out the invention will be hereinafter'described,together with other features of the invention.

The invention will be more readily understood from a reading of thefollowing specification and by reference to the accompanying drawings,in

which an example of the invention is shown, and

wherein:

Figure 1 is a view, partly in section and partly the improved method,

Figure 2 is a vertical, sectional view of thelower end of the boreshowing the cement in place,

sure in the well bore to prevent flow from the oil Figure 3 is atransver e, vertical, sectional view of the control valve, v

Figure 4 is an enlarged, horizontal, cross-sectional view, taken on theline l-l-of'Figur'e 3,

Figure 5 ,is an enlarged,hori zontal, cross-sec tional view, taken onthe line 5 5 of Figure 3,

Figure 6 is a transverse, vertical, sectional view of thepacker, and Vapparatus for carrying out ed or closed position.

Figure 7 is a view, similar to Figure 1, showing the apparatus withoutthe well'packerassembly.

In the drawings, the numeral l9 designates a well bore which has beenillustrated as extending through an oil and gas producing formation orstratum A and into a water sand or formation B which is locatedimmediately below the oil'and gas formation. A well casing II isdisposed within the bore and has its lower end cemented, or otherwisesecured in place withinsaid bore, said lower end terminating adjacentthe upper portion of theoil stratum A. The upper end of the casingprojects from the well bore and has the usual casing head 12 securedthereto. The head is provided with an outlet pipe l2a through whichcommunication with the interior of the casing may be established. A welltubing l3 extends axially through the casing head and casing and issuitably supported in said head. The upper end of the tubing isconnected by an elbow Ma with a pipe H which may serve either as aninlet or outlet to conduct fluids to and from said tubing. The lower endof the tubing terminates at the lower end of the well bore and may reston the bottom thereof, as is illustrated in Figure 1.

As hereinbefore stated, the location of a water sand immediately belowthe oil and gas producing formation in a well bore permits the'water toflow into the bore and interfere with the natural flow from the oil andgas formation. The water enters the bore and flows upwardly, channellingthrough the well fluids. If the condition is present for any length oftime, the water may wash away the wall of the bore, and eventually, saidwater impedes and interfereswith the flow from the formation A to suchan extent that the well is killed and no oil and gas is produced. It istherefore, notonly desirable but essential that the water formation B beclosed so as to prevent the flow of water.

In carrying out the invention, a valve 15 is connected in the tubingstring l3 near the lower end thereof. This valve includes a tubular bodyl6 (Figure 3) which has its upper end connected to the tubing by acoupling collar H. The lower portion of the collaris threaded into theupper end of the body and the bore 18 of the collar is tapered orreduced toward its lower end. An annular valve seat l9 surrounds thelower end of the bore and is arranged to be engaged by a valve member20. The valve member includes a cylindrical head 2| having an annularbevelled seating surface 22 at its upper portion; and above the seatingsurface the head is reduced to provide a conical tip 23. The head ismovable within the bore 24v of the tubular body and has radial guidewings or ribs 2 la on its exterior surface for holding said head inaxial alinement as it moves within the bore. Manifestly, when the headis in itsuppermost position within the bore, the bevelled surface 22thereof is engaging the seat to close the bore of the collar l1. g

The valve head is provided with an axial dc pending guide stem 25 whichhas its lower end slidable in an elongate sleeve 26. The sleeve ismounted within a transverse spider 21 which is formed within a collar 28threaded into the lower end of the bore of the body IS. A coiled spring29 surrounds the stem and its upper end engages the underside of thevalve head while its lower end rests on a follower ring 30 which issupported on the sleeve 26., The spring constantly exerts its pressureto urge the valve head to a seat- It will be evident that with the valvehead in its seated position. any fluid pressure below the valve memberis added to the spring to hold said valve'closed and in order to unseatthe valve head, a pressure must be built up in the tubing l3 above thehead suiilcientto overcome the pressure acting from below plus thespring pressure. Thus, the valve member is operable by the pressuredifferential thereacross and by varying the tension or pressure of thespring 29, the differential necessary to operate the valve may bevaried.

The collar 29 which is mounted in the lower end of the tubular body isconnected by a swaged nipple 9| and coupling 92, with the upper end ofthe tubular mandrel 33 of a well packer 34. The packer may be of anydesired construction and, as illustrated, includes the mandrel having anupper confining thimble 35 secured thereon. An annular elastic packingsleeve 33 surrounds the mandrel with its upper end engaged within thethimble 35. A lower thimble 31 is slidable on the mandrel and has thelower end of the packing member engagedtherein. The lower thimble iscoupled to an anchor tube 39 which is arranged to rest on the bottom ofthe well bore. The tube is formed with a plurality of inlet openings 39to establish communication between the interior of the well tube and thewell bore.

In cementing oi the water sand or formation B, the valve I5 is connectedin the tubing string l3 and the well packer 34 is mounted below thevalve as has been described. A suitable fluid or liquid under pressureis then introduced into the casing H and this'fluid is preferably an oilso as not to contaminate the producing formation A with a foreignsubstance. The fluid is under a suflicient pressure to kill the well andprevent a flow of well fluids from the formation A or a flow of waterfrom the water sand B.

After flow into the bore has been halted, the tubing string l3 havingthe valve l5 and packer 34 therein is lowered until the anchor tube 38strikes the bottom of the bore. At such time, a

continued lowering of the tubing imposes the weight of the tubing on theelastic packing sleeve 36 of the packer, whereby said sleeve isdistorted radially outwardly into sealing contact with the wall of thewell bore. It is preferable that the anchor tube be of such length thatthe packer is located at the. lower end of the oil producing formationA, whereby the sealing occurs at this point.

During the lowering of the tubing string the valve element 20 is in aclosed position with the valve head 2| engaging the seat 19 whereby flowthrough the tubing is prevented. The valve head is held in its seatedposition by the coiled spring 29 and also by the pressuremf the fluid inthe bore outside the tubing, which pressure is acting against theundersideof the valve element through the openings 39 and bore of thetube and mandrel. P

After the .packer has been set, as described, the cement is introducedinto the upper end of the tubing l9 through the-pipe l4 and this cementfalls downwardly through the well. tubing and its downward movement ischeckedby the closed -TaTlve element 20. The cement ismaterially heavierthan the fluid column outside of the tubing and, therefore, the coiledspring 29 is of such strength as to compensate for the diiference inweight betweenthe cement and the fluid in the bore, whereby this springplus the fluid pressure is suflicient to-hold the valve bore.

, 2,268,010 3 is to be introduced. Therefore, the cement is (not shown).As explained, the weight 'of the column alone is' not 'suflicient tounseat the valve element. As a pressure is built up above the cementcolumn, the differential across the valve element is increased until thefluid pressure and spring acting to hold the valve closed, is over comeand at this point the valve element is unseated to allow the cement toflow downwardly through the packer and tube and into the well' This flowof the cement into the bore will be retarded by the fluid pressure and,therefore, such flow will be relatively slow. As the cement enters thebore, it flows outwardly into the formation B because said formation isrelatively porous and offers less resistance than the fluid pressure inthe well bore. Therefore, the cement drives the water deeper into theformation B and follows said water. In actual practice, the cement willforce the fluid pressure below the packer back into,- the formation andwill completely encircle the anchor tube, 39. The packer being inan'expanded position will prevent a direct upward flow of the cementaround the tubingand any tendency of the cement to by-pass around theexterior of the packing sleeve 36 will be defeated by the fluid pressurein the bore acting on the the producing formation A will set up aresist-- ance to the flowing cement and since said cement will naturallyfollow the line of least resistance, it will flow deeply into the watersand B to completely plug the same. The. arrangement forces the cementto travel in a substantially lateral or horizontal plane whereby thewater sand B is sealed off. After the cement is introduced into theformation B, the tubing is raised so as to permit the cement to flll thelower end of the bore. The fluid pressure is maintained' in the boreoutside the tubing until the cement hardens. Manifestly, the cement doesnot enter the oil and gas formation A and does not interfere withnatural flow therefrom where the fluid pressure in the casing and boreis removed. A

It is obvious that the valve i5- provides a means whereby the column ofcement may be sustained in the tubing until it is desired to introducethe same into the formation. By properly controlling the fluid pressurein the bore outside the tubing and the pressure above the cement column,it is possible to eject the cement from the tubing substantially at anydesired rate. This eliminates the cement rushing from the lower end ofthe tubing and upwardly into the casing and bore, which action is causedby the uncontrolled weight of the. cement column.-

Therefore, the method contemplates 'control of the cement as it isforced into the formation.

The control of the cement is accomplished by the valve and, since thespring 29 of the valve l5 may be readily changed to compensate forvariations in the height of the cement column,

' formation A. It will be manifest that the maintenance ofthe fluidpressure in the bore and on a simple control valve capable of operatingunder various conditions and at various pressure differentials is had Itis pointed out that although the use of a well packer has been founddesirable, it is not essential to the invention. This packer may beentirely eliminated, as shown in Figure '7. When the packer is omitted,the pressure of the fluid column in the bore is suflicient to permit thecement from travelling upwardly in the bore since such pressure presentsgreater resistance 1 to the flowing cement than does the water sand orformation B.

'. The foregoing description'of the invention is explanatory thereof andvarious changes in the size, shape and materials, as well as in thedetails ;of the illustrated construction, may be made, within the scopeof the appended claims, without departing from the spirit of theinvention.

What I .claim and desire to secure by Letters Patent is:

l. The method of cementing a water stratuir which is adjacent andbelowan'oil producing stratum which consists in, introducing a fluid underpressure into the well bore to halt natural flow from the strata,packing off between the water and oil strata, introducing a column ofcement into the well bore, sustaining the column in the lower end ofsaid bore, applying a pressure .to the upper end of the column to forcethe same into the bore against the fluid pressure therein, and utilizingthe pressure of the fluid in the bore-to force the cement to travelradially of p the boreand laterally into the water stratum to plug thesame. r I

2. An apparatus for cementingoff the water formation of a well boreincluding, a tubular conductor adapted to extend axially through thewell'bore, means for creating a fluid pressure within the bore ,toprevent natufal flow, from the formation into the bore, meansfor-packing off between the conductor and thebore above the waterformation, a valve in the lower end of the conductor having one sideexposed to the pressure in the bore whereby such pressure urgesthe valveto a closed position, means for introducing cement into the conductorabove the the formation into the bore, means for packing off between theconductor and the boreabove the up variations in pressures in the bore,etc., whereby water formation, a valve 'in the lowe'r end of theconductor having one side exposed to the pressure in the bore wherebysuch pressure-urges the valve to a closed position, a resilientmeansassociated with the valve for also urging the valve to a closedposition, means for introducing cement into the conductor above theclosed

